How to make objects clickable hyperlinks in WebGL?
First (if you haven't already), download the Blend4Web SDK and be sure to install it correctly. The SDK is different from the standalone add-on, so make sure you get the SDK (which includes the full-featured add-on, and also a lot more).

Set your render engine to Blend4Web.



Enable Blend4Web's Logic Editor and create a new node tree by clicking the [+] button.



In Blender's Node Editor, set the node tree type to Blend4Web logic, and select your node tree.



Make a node setup like this to instruct it to redirect to another URL when an object is clicked:



This node setup specifies that IF Suzanne (the monkey) is clicked, the redirect will happen, ELSE go back to listening for a click. That's why the "Miss" output routes back into the "Previous" input in a loop.

You can click the Fast Preview button on the right of the 3D Viewport's menu to preview it in your browser.

Once you're happy with the results, choose File > Export > Blend4Web (.html) to generate the standalone HTML file with all the 3D and interactivity data bundled into it.

Here's an example .blend (requires that the Blend4Web SDK be installed):


And here's an example HTML file generated from the .blend to demonstrate the functionality (requires that WebGL be enabled in your browser).